Study 7 Chapter 7 Sec.1 Cell Discovery and Theory flashcards from Joselyn L. With cells passing copies of their genetic material on to their daughter cells. Read and Download Cell Discovery Theory Study Guide With Answers Free Ebooks in PDF format - 70 HP EVINRUDE OUTBOARD MANUAL HOLT MCDOUGAL LESSON 12 70 HP EVINRUDE REPAIR. View Test Prep - Study Guide 7 Answers from BIO-L 112 at Indiana. Answers to Chapter 7 Study Questions 1. The plasma membrane of a cell exhibits selective permeability.

• Study Guide Section 1: Cell Discovery And Theory
• Cell Discovery And Theory Study Guide
• 7.1 Cell Discovery And Theory Worksheet

. There are many discoveries that have changed the course of science and the world. Nikola Tesla’s discovery of alternating, for example, helped pave the way for widespread access to electricity, and Louis Pasteur’s discovery that and disinfectant could kill improved food safety and saved millions of lives. In 1655, the English scientist made an that would change the study of biology forever.

While examining a thin, dried section of cork tree with a crude microscope, Hooke observed that he could plainly see the cork to be made up of tiny spaces surrounded by walls, much like a honeycomb, but that the spaces were irregular and shallow (Figure 1). Further, Hooke noted that these 'little Boxes' were so numerous that there were 'in a square Inch above a Million. And in a Cubick Inch, above twelve hundred Millions sic' (Hooke, 1655). Figure 1: The cork described in Micrographia by Robert Hooke.

In his landmark book Micrographia, Hooke called these spaces 'cells' because they resembled the small rooms monks lived in ( cella in Latin). What Hooke’s samples were not able to reveal at the time, though, was that are not in fact empty. Though he was diligent in looking at his samples through different magnifications and with various sources and angles, there were two major obstacles that stood in Hooke’s way of discovering subcellular structures. The first was that the microscope he was using at the time was still too low of a magnification to show that much was contained within the walls of the cells. The second: His samples were of cork – composed of long-dead cells, absent of any. Antony van Leeuwenhoek improves microscopy In the years immediately following, other scientists would build on the work of Hooke, including Antony van Leeuwenhoek (1632 – 1723), a cloth merchant in Delft, Nederland.

Van Leeuwenhoek was not a scientist by formal training, but he was an industrious and curious individual who took great joy in observing the world around him (Anderson, 2009). While working in his haberdashery in the 1670s, van Leeuwenhoek began to with glass-blowing and the construction of microscopes (Figure 2). Using the designs described by Hooke in Micrographia, van Leeuwenhoek built his own microscopes by hand, fabricating every element from the highly-refined lens to the screws used to hold the instrument together (Anderson, 2009). Figure 2: van Leeuwenhoek's simple microscope. On the brass plate is a small magnifying lens mounted and a sharp point that would hold the specimen. Turning the screws would adjust the position and focus. During his lifetime, van Leeuwenhoek constructed hundreds of microscopes and lenses by hand, each one unique.

It was with these microscopes and improved lenses that he began to study the world around him and share these with institutions like the English. One of his first important observations came in August 1674, when he looked at water samples from Berkelse Meer, a lake two miles outside of Delft. In a letter to that September, and published in Philosophical Transactions of the Royal Society, van Leeuwenhoek noted: I took up some of it the water in a Glass-vessel which having viewed the next day, I found moving in it several Earthy particles, and some green streaks, spirally ranged. Among all of which there crawled abundance of little animals some of which were roundish; those that were somewhat bigger than others were of an Oval figure: On these latter I saw two legs near the head and two little fins on the other end of their body. The motion of most of them in the water was so swift, and so various, upwards, downwards, and round about, that I confess I could not but wonder at it. I judge, that some of these little creatures were above a thousand times smaller than the smallest ones, which I have hitherto seen.

What van Leeuwenhoek was seeing, we can now presume, were some of the smallest forms of life: protozoa, rotifers, ciliates, and. Van Leeuwenhoek’s descriptions are among the first to identify the unique features of these different and was the beginning of the discipline we now call microbiology – the study of microscopic organisms. Comprehension Checkpoint The first formal statement in cell theory was that:. a.Every cell has a nucleus. b.All living things are made of cells.

Prokaryotes and eukaryotes: The case for a shared ancestry While all life is made up of, not all cells have the same structure. In the organization of living things, fall into one of two groups: and. Prokaryotes (archaea and bacteria) and eukaryotes (fungi, plants, animals, and protists) have many defining factors that are different from one another, but their similarities are very important and form the foundation on which a of shared ancestry is built. All and consist of with ribosomes suspended in it, the genetic material of and, and are enclosed in a. These common are chemically and structurally almost indistinguishable.

The consists of a bilayer, which is a fatty film that surrounds the (see our module to learn more). This membrane contains several structures that allow the cell to perform necessary tasks, including pumps and channels that allow substances to move into and out of the cell, and receptors that allow the cell to sense what is in its surroundings and be recognized by other cells (see our module).

This plasma membrane forms a semi-permeable barrier that keeps the cell’s cytosol from leaking out and the surrounding from leaking in. Cytosol is a gel-like consisting of water packed with dissolved, wastes, and many other. Many take place in the and it contains and filaments that provide shape to. Suspended within the cytosol are ribosomes – large molecular machines responsible for translating the information contained in into proteins. The number of ribosomes in a cell depends largely on the cell’s function. (See Figures 5 and 6 for illustrations of the cell structures.) Figure 5: A diagram of a typical animal cell. Figure 6: A diagram of a typical plant cell.

Both and also have genetic material (DNA and RNA), which carries the instructions for the production of (see our module series). However, likely the most important distinction between the two taxa of is that the genetic material of eukaryotes is enclosed within a double, creating a. Prokaryotes have no such membrane-bound nucleus; their genetic material exists in a nucleoid – an irregularly shaped region within the. Although a bacterium seems much different than a mold, and a tree seems very different from a human, inside the of all these many things are very much the same. This argues that all living things on Earth are related and descended from a common ancestor.

This is called the Theory of Universal Common Descent. Consider the following: Figure 7: A comparison of Ribonucleic acid (RNA) and Deoxyribonucleic acid (DNA). All living things use DNA for their genetic material. Hypothetically speaking, there are dozens of molecules that could function as a repository of genetic information.

In fact, proteins and sugars might have been 'better' choices than DNA, since they would allow much more information to be stored in the same size molecule. However, every living cell stores their genetic information in the form of chromosomes made of DNA. In addition, all living things use the same four nucleotides as the building blocks of DNA. Nucleotides could be built in an almost infinite number of ways, but only four are used by life on Earth (Figure 6). The genetic code is universal.

Not only do all living things store their genetic information using the same molecule, the code for reading the information is identical as well. For example, in a given DNA sequence, Cytosine-Thymine-Cytosine (CTC) codes for the amino acid leucine. This is true in every living cell from bacteria to humans. There is no reason why this would have to be true.

The genetic code is like Morse Code: it is purely arbitrary. Any number and combination of DNA nucleotides could serve as a code for any given amino acid. And yet, all life uses the exact same code. (There are a couple of exceptions, but these are very rare.) This common feature of life is what allows us to insert genes from one species into another and have those genes still work properly. For example, it would be extremely expensive to harvest insulin from human donors in order to treat patients with diabetes. Instead, scientists have engineered bacteria that contain the human insulin gene.

The gene is read and interpreted the same way in both cells, so the bacteria build a perfectly functional human insulin molecule. All cells convert chemical energy in similar ways. The energy that reaches the planet from the sun could be harvested in an almost infinite number of ways. However, the process and enzymes for photosynthesis are strikingly similar among all photosynthetic cells, from cyanobacteria and plankton to oak trees and lily pads. Similarly, all cells consume macromolecules and convert their energy in astonishingly similar ways. The enzymes of glycolysis, the process of breaking down glucose, are shared among all living cells. In addition, all cells make and use ATP molecules as their general “currency” for transferring energy in its many chemical reactions.

There are literally thousands of molecules that could be used for this purpose, including many that would function more efficiently than ATP. The chemical reactions of energy conversion are remarkably similar in all cells on Earth. All ribosomes are structurally and functionally similar. Structures called ribosomes are responsible for interpreting the genetic code of DNA, received in the form of mRNA, and building proteins according to that code.

The ribosomes of all prokaryotes are almost exactly the same, and so are the ribosomes of all eukaryotes. Between eukaryotes and prokaryotes, although there are differences, the overall structure is remarkably similar. All ribosomes have two parts: a big subunit and a small subunit. They operate in nearly identical mechanisms.

All biological membranes are similar. From the plasma membrane of bacteria to the nuclear envelope of animals, the water-tight membranes that establish separate compartments within and around a living cell are extremely similar. On the one hand, this is no surprise because the properties of phospholipids are quite unique. On the other hand, starting with very basic chemical building blocks, like those found on the early Earth, many possible membrane-forming molecules could have emerged. In fact, scientists can now synthesize much better, simpler, and more stable membranes. That all life uses the same basic membrane structure is strong evidence that once membranes first evolved, they were passed to descendants with little changing along the way. These are but a few of the pieces of for the Theory of Universal Common.

Prokaryotes have been documented in the as far back as 4.2 billion years (see Figure 8)., however, can only be documented as far back as 2.7 billion years, leaving 1.5 billion years of to take place between. For this reason, scientists believe that eukaryotes evolved from long after the central features of living had already emerged. Figure 8: A timescale of prokaryote evolution. From the article by Battistuzzi, F.U., Feijao, A., and Hedges, S.B. A genomic timescale of prokaryote evolution: insights into the origin of methanogenesis, phototrophy, and the colonization of land. BMC Evolutionary Biology, 4: 44. Image © 2004 Battistuzzi et al.

The defining feature of, the, first evolved as an in-folding of the plasma, which formed a compartment to house and protect the. This in-folding evolved into the nuclear envelope – the double membrane of the nucleus (Figure 9). In addition, as discussed in our module, the Theory of Endosymbiosis suggests that a small was able to penetrate the of a larger, anaerobic, probably an archeon, and survive, living symbiotically with the host. Over time, the small aerobic bacteria evolved into the we know today as the mitochondrion. Figure 9: The cell membrane in-folding and creating a nuclear envelope.

Comprehension Checkpoint The Theory of Universal Common Descent argues that. a.all living things descended from a single ancestor. b.cells without a nucleus evolved long after the existence of cells that contain a nucleus.

Differences between cell types: Organelles and their functions All basic chemical and physiological functions – repair, growth, movement, communication, digestion – are carried out inside of, and the activities of cells depends on the activities of the structures within the cell (including the organelles). This means cells can convert from one form (which, depending on the cell type, can be in the form of, or other compounds) into another. For example, cells can digest the building blocks of other that it has eaten and used the released energy to build its own materials such as, carbohydrates, and fats. Most of the activities of a are carried out via the production of. Proteins are large that are made by specific within the cell using the instructions contained within its genetic material (see our series on DNA:, ). Depending on the type of, specific organelles may or may not be present in a cell.

In addition to the plasma (cell), ribosomes, and, the typical components of include:, transport, endoplasmic reticulum, Golgi bodies, and lysosomes. In addition to these, photosynthetic (plant) cells will have a cell wall, and a central vacuole.

Prokaryotic, however, do not contain any membrane-bound. Instead, they can include plasmids, a cell wall, and in the case of photosynthetic, thylakoids. Table 1, below, lists the function of each type of organelle and which group of cells it is found in. Membrane-bound Organelles Independently replicating Mitochondrion (plural: mitochondria) The “power supplier” for the cell, generating most of the ATP used in cell processes through the conversion of nutrients into energy. Also involved in cell signaling, controlling the cell cycle and cell growth, and cellular differentiation.

Found in all eukaryotes. Chloroplasts A chlorophyll-containing plastid responsible for converting sunlight and carbon dioxide into oxygen and sugar. Found in plants and algae. Endomembrane System Smooth Endoplasmic Reticulum A series of sac-like membranes responsible for the synthesis and storage of lipids, phospholipids, and steroids, as well as the metabolism of carbohydrates. Rough Endoplasmic Reticulum A series of sac-like membranes studded with ribosomes, responsible for the synthesis and export of proteins Golgi Apparatus Functioning like a distribution center, the Golgi Apparatus gathers simple molecules and creates more complex molecules.

Once created, those complex molecules are transported to other organelles, stored in vesicles, or exported from the cell. Plasma Membrane A layer of phospholipids and proteins that forms a barrier between the inside of the cell and the outside environment. Cell Wall Found in plants, fungi, and some protists, a structure outside of the plasma membrane that provides strength, support, and protection. Lysosomes A specialized compartment containing hydrolytic enzymes. The role of lysosomes is to digest sugars, proteins, and other “foods” a cell absorbs. Nuclear Envelope A double-membrane surrounding the nucleus. This membrane provides a barrier between the nucleus and the cytosol.

Peroxisome Similar to lysosomes, these contain enzymes used in a variety of reactions, including oxidation reactions. In plant seeds, peroxisomes convert stored fatty acids to carbohydrates, providing energy for germination. In plant leaves, they are involved in photorespiration. Vacuoles A compartment used for storage of nutrients, water, and waste.

In plants, the central vacuole plays an important role in providing structure. Vesicles A small spherical compartment composed of a lipid bilayer and internal fluid used to exchange cargo between organelles of the endomembrane system. Specialized vesicles play a variety of roles. Cytosol Otherwise known as intracellular fluid (ICF), the liquid matrix found within a cell that holds other organelles and allows intracellular processes to take place.

Comprehension Checkpoint The production of allows the cell to carry out most of its activities. a.sugars. b.proteins Cell theory expands In 1855 German biologist Rudolf Virchow realized that the widely held idea that spontaneously generate out of non-living did not make sense, and an idea proposed by Polish-German embryologist might be correct. Remak, a friend and colleague of Virchow, had put forth the idea that generate from preexisting cells, and not from things like dust and dead fish. Plagiarizing Remak’s idea, Virchow officially added to cell in 1858 with the statement: Every cell originates from another existing cell like it. This statement, along with Schwann's declaration that 'All living things are made of cells,' forms the basis of modern cell theory. While it is true that all are produced by the division of preexisting cells (in other words, through reproduction), we now know that the of how cell reproduction takes place differs between and – and that the speed at which it takes place within those two groups also differs.

Prokaryotes replicate through, a by which a single simply divides itself in half. Because prokaryotes are single-celled, every time a cell divides it is reproducing. Prior to the fission, the genetic material (DNA) is copied within the cell; then the two of attach to opposite sides of the.

The membrane then grows between the two molecules, forming a separation. When the prokaryote has doubled in size, the cell begins to pinch inward and a cell wall forms, dividing the cell in half (see animation). Eukaryotes, however, reproduce through a more complicated involving several phases, including interphase, and (see our module). During the first half of interphase, called the G1 phase, take in and nearly double in size.

Then, in S-phase, the inside the cell’s replicates, making a complete copy of itself. Following this is the G2 phase, where the cell checks and corrects any errors that may have occurred in that DNA and grows a little bit more. If all has gone well, the cell proceeds to mitosis, or M phase, when the two DNA copies are separated and the nucleus splits to create two identical nuclei. Finally, the rest of the cell splits in two, each with its own new nucleus, in a process called cytokinesis.

All contain genetic material in the form of that is passed from the cell to the two cells. However, in that genetic material is in a circular form, while in the genetic material is in linear strands. For prokaryotes, is a means of reproducing and increasing numbers of the. For example, Salmonella can grow so fast that the population doubles every thirty minutes. This means that a single Salmonella bacterium sitting on a tiny piece of raw chicken left in the kitchen sink after dinner can give rise to a million descendants by the next morning.

However, most are multicellular. Most of the division that takes place is not to produce more, but rather to allow the organism to grow and develop and to repair and renew tissues. Nevertheless, each and every cell division follows the same complex pattern. Even the most rapidly dividing human cells take more than twenty hours to a complete a single division cycle (with only very rare exceptions). In addition, it is not just the and the that must be duplicated and split between the two cells: cells contain many specialized suspended in their cytosol. During cell division, the many organelles must expand, split up, and be distributed more or less evenly between the two daughter cells. Unlike the other eukaryotic organelles, and contain their own unique genetic material.

They replicate themselves independently when more are needed and are then passively distributed to the two daughter cells during. Comprehension Checkpoint In eukaryotes, the main purpose of cell division is to. a.repair and renew tissues in the organism. b.make new organisms. Cell variety within organisms Cell diversity extends beyond the differences between and, and between the different kingdoms of (plants, animals, etc.). There are also major differences in within an individual organism, reflecting the different functions cells perform. For example, the human body consists of trillions of cells, including some 200 different cell types that vary greatly in size, shape, and function.

The smallest human cells, sperm cells, are a few micrometers wide (1/12,000 of an inch), whereas the longest cells, the neurons that run from the tip of the big toe to the spinal cord, are over a meter long in an average adult. Human also vary significantly in structure and function.

For example, only muscle cells contain myofilaments – protein-containing structures that allow the cells to contract (shorten) and, as a result, cause movement. The eye contains specialized cells called photoreceptors that have the ability to detect. These cells contain special chemicals called that can light and special structures that release chemicals onto other cells which can then send electrochemical to the brain, a we perceive as vision. Plants also contain a wide variety of types. There are specialized cells called collenchyma that provide structure without restricting growth and flexibility.

These cells lack secondary cell walls, and their primary cell walls lack a hardening agent, which especially helps young plants grow quickly and be resilient to wind and water. Other types of plant cells include xylem, whose purpose is to transport water throughout the plant, and phloem, whose purpose is to transport. The realm of cellular discovery is one that is still alive and well, despite its extensive history. In 2013, a group of European scientists identified a new inside the of tannin-producing plants, like grapevines and tea trees (Brillouet et al., 2013). Called tannosomes, the organelles originate within the and are responsible for creating the bitter tasting polyphenol that wards off predators and gives wine and tea their familiar “dry” feeling in the mouth.

And in the same year, researchers in the United States identified that the types of developed by ribosomes occurred in phases along with the phases of the cell cycle (Stumpf et al., 2013). Identifying which proteins are produced when has implications for cancer, since currently exist suggesting inefficient protein (translation) in cancer cells. While it is easy to think that modern technological advances means that we’ve discovered all the components of cells, we must remember that, like, there are sometimes things preventing us from seeing everything and that new discoveries may still await.

This module is an updated version of our previous content, to see the older module please go to this. Summary Cells are the basic structural and functional unit of life. This module traces the discovery of the cell in the 1600s and the development of modern cell theory. The module looks at similarities and differences between different types of cells and the relationship between cell structure and function. The Theory of Universal Common Descent is presented along with evidence that all living things on Earth descended from a common ancestor. Key Concepts. Cells are the basic structural and functional unit of all living things and contain inheritable genetic material.

The activity of a cell is carried out by the sub-cellular structures it possesses. Cells possess an outer boundary layer, called a cell membrane, cytoplasm, which contains organelles, and genetic material. There is considerable variety among living cells, including the function of membranes and subcellular structures, and the different types of functions the cells carry out, such as chemical transport, support, and other functions. NGSS.

HS-C6.1, HS-LS1.A1. Further Reading. References. Anderson, D. Overview: The curious observer.

Lens on Leeuwenhoek. Retrieved from:. Brillouet, J. M., Romieu, C., Schoefs, B., Solymosi, K., Cheynier, V., Fulcrand, H.,. The tannosome is an organelle forming condensed tannins in the chlorophyllous organs of Tracheophyta. Annals of Botany, 112(6), 1003-1014. The birth of the cell.

New Haven, CT: Yale University Press. Micrographia: Some physical descriptions of minute bodies made by magnifying glasses with observations and inquiries thereupon. London: The Royal Society of London.

Leeuwenhoek, A. More observations from Mr. Leeuwenhoek in a letter of Sept. 7, 1674 sent to the publisher. Philosophical Transactions of the Royal Society, 9, 178-182. Schwann, T. Microscopic investigations on the accordance in the structure and growth of plants and animals.

Smith, Trans.). London: The Sydenham Society. (Original work published in 1839). R., Moreno, M.V., Olshen, A.

B., Tayloremail, B. S., Ruggero, D.

The translational landscape of the mammalian cell cycle. Molecular Cell, 52(4), 574-582. Heather MacNeill Falconer, M.A./M.S., Nathan H Lents, Ph.D. “Discovery and Structure of Cells” Visionlearning Vol. BIO-1 (2), 2003.

Robert Brown We owe so much of what we know about our world to the studies of scientists who have worked hard over past and current centuries. One of those scientists is Robert Brown, a Scottish born, brilliant scientist during the early 1800s that conducted studies in England and Australia. Robert Brown was a regarded botanist Robert Brown focused most of his studies in the field of botany, which is the study of plants.

He eventually focused even deeper in the field of botany by studying in the field of palynology, which is the study of living and fossilized plant pollen, spores, and microscopic plankton. Brown also conducted studies in paleobotany, the study of the evolution of plants through geologic history to confirm the fossil record. It's time to look at his contributions to science and our world. Cell Theory During the time of Robert Brown conducting studies, there were many scientists seeking to understand more about what makes up plants and animals. Several scientists realized that there were cells present in both plants and animals, but they did not know the functions of most cells or what was inside of the cells. Well, Brown was studying and breeding plants. He knew that it took pollen grains in order to create new plants.

While watching the process of pollen grains fertilizing a plant, he noticed that there were ovals inside the plant cells and the pollen was moving in and out of the ovals. He realized that the ovals were of great importance to the cells and called them the nucleus of the cell. The nucleus, as we clearly know now, is like the brain of the cell that contains DNA and directs everything that takes place in the cell. Brown named and discovered the function of the nucleus Through Brown's studies, he was able to recognize that the nucleus of the plant cells was necessary for fertilization and subsequent embryonic development to occur.

Brown published his research findings and gave speeches. His discovery of the nucleus and its role helped to put together the cell theory. The cell theory states that 'All living organisms are composed of cells and cells come from pre-existing cells'. Brown's discovery helped to confirm the second half of the cell theory. Discoveries and Contributions Brown had even more discoveries beyond the nucleus. While dropping out of school is often viewed as failure, it became anything but for Brown. Early on in his career, he worked with another scientist named William Witherton.

Robert was collecting and viewing different plant specimens and came upon one that had not been previously identified. He had discovered a new species of grass that became known as Alopecurus alpinus. A handful of plants discovered by Robert Brown. The third from the left is Alopecurus alpinus The discovery of that plant was the first of many. As a matter-of-fact, Brown would ultimately discover and help to name over 2000 new species of plants during his time of studying in Australia. He also collected over 3400 different species of plants to include the 2000 new ones that he discovered. Brown felt that the way that plants were classified was not accurate and too strict.

So, he identified and classified plants differently from how some other scientists classify plants. He published his way of identifying plants and it gained wide acceptance because it supported an already proposed classification system known as the 'natural system'. This contribution added several new genera and families of plants to the natural classification system. There is of course a discovery that carries Brown's name. Afterall, that is what scientists do, right?

Name a discovery after themselves! As Brown was viewing pollen grains under the microscope, he observed that they were making slight, random movements. He started to view other substances and realized the movement occurred in many different substances, including glass and rock. Brown noticed that the slight, random movement he was seeing only occurred when the particles inside of the substance were a certain size or smaller. He never figured out what caused the movement, but he did name it Brownian movement.

Study Guide Section 1: Cell Discovery And Theory

In the next century, a scientist you probably heard of named Albert Einstein proposed that the movement was due to the particles running into molecules. Another scientist named Jean Perrin proved what Einstein thought and this discovery gave rise to the identification and proof that atoms exist! That was a very big discovery when you consider everything that we use atoms for.

Beyond his great discoveries, he also made a huge contribution to science by sharing his knowledge and results of his and another scientist's studies. Brown worked with a scientist named Sir Joseph Banks. Banks had created a whole library detailing the different species and classifications of plants.

Banks thought enough of Brown that he willed it to him. The library collection was supposed to be sent to the British Museum upon Brown's death. Instead of that happening, Brown convinced the British Museum to create a botanical department in the museum that would house the library collection.

Cell Discovery And Theory Study Guide

Brown was instrumental in getting it started and running it until his death. Lesson Summary Brown did a lot with his life, so let's recap. Robert Brown was a Scottish born scientist during the early 1800s that conducted studies in England and Australia. He did research in the following areas:. botany - the study of plants. palynology - the study of living and fossilized plant pollen, spores, and microscopic plankton. paleobotany- the study of the evolution of plants through geologic history to confirm the fossil record Robert Brown discovered and named the nucleus, which is the brain of the cell that contains DNA and directs everything that takes place in the cell.

7.1 Cell Discovery And Theory Worksheet

His discovery of the nucleus and its role helped to prove the cell theory - 'All living organisms are composed of cells and cells come from pre-existing cells'. Other discoveries and contributions include:. Discovery and naming of over 2000 species of plants.

Adding genera and families to a classification system. Brownian movement - slight, random movement of small particles in a substance. Helped develop and run the botanical department of the British Museum.