Lec. 6 Leaves, Fruits, Seeds Or Animals?

Question 1

What are cotyledons?

Answer 1

primordial leaves preformed in the seed.

Question 2

What happens to your body if you
1. eat raw beans,
2. raw castor beans
or 3. raw corn?

Answer 2

1. Raw beans: makes you sick
   , 2. Raw castor beans: can kill you,
   3 raw corn: nothing

Question 3

Name two key differences between plant seeds and mammal babies.

Answer 3

Developing seeds have no access to nutrients provided by their mothers. Seeds can remain dormant in the ground until they sprout and start growing.

Question 4

Give an example of a plant that produces an ocean-going seed that transports
its own water.

Answer 4

Coconut

Question 5

What happens to the fat inside a coconut when the seed germinates?.

Answer 5

it is transformed in sugar so the the growing palm can make cellulose.

Question 6

How is it possible that Strychnos is an edible fruit if the plant is the source of
strychnine?

Strychnos

Answer 6

The toxin is in the seeds, not in the sweet fruits flesh.

Question 7

What is coprophagy?

Answer 7

the eating of feces.

Question 8

What is the different between a pollen grain and a seed?

Answer 8

The pollen grain contains the male gametes (two sperm) and the seed contains a plant embryo (plus nutrients).

Question 9

Give an example each of a plant each, that has a pattern of flowering that is
bisexual, monoecious=separate male and female flowers on same plant, and dioecius=male and female flowers on separate plants.

Answer 9

tomato, cucumber, date palm

Question 10

What does double fertilization in flowering plants refer to?

Answer 10

the fact that one sperm in the pollen tube fertilizes the ovule (egg cell) and the other fuses with a diploid cell to form the seed nutrients (endosperm).

Question 11

Give two examples of plants that have separate male and female plants:

Answer 11

Date palms and Kiwi.

Question 12

Give three examples of important crops that are propagated asexually.

Answer 12

banana, taro and cassava.

CASSAVA

Question 13

What is the distinguishing feature of monocot plants versus dicot plants?

Answer 13

Monocots sprout a single, dicots two leaves

Question 14

List five of each, monocot and dicot crops:

Answer 14

Monocots:
onion,
corn,
coconut,
garlic,
turmeric

Dicots:
beans
spinach
cabbage,
passion fruit,
avocado

Question 15

Which plant was domesticated first, the apple or wheat?

Answer 15

wheat

Question 16

What is the meaning of polyploidy?

Answer 16

multiple copies of chromosomes in the genome.

Question 17

Why would farmers repeatedly have bred plants into polyploid varieties?

Answer 17

bigger plants, seeds and fruit.

Question 18

How can one prepare DNA from living cells?

Answer 18

• Detergent, water and salt mixed to lyse the cells (lipid rich membranes of the cell and the nucleus dissolve);
• Straining away the rough parts;
• Adding cold rubbing alcohol to precipitate the DNA from the soap salt water solution into white slimy goop.

Question 19

Which large animals used to disperse avocado seeds in Central America?

Answer 19

extinct elephant relatives

Question 20

What are the four classes of major biomolecules?

Answer 20

Nucleic Acids, Proteins, Glycans, Lipids.

Question 21

Which two classes of biomolecules are not directly encoded in the genome?

Answer 21

Glycans and Lipids.

Question 22

If one of your cells were 1000 times bigger than real life, how long would the genome (haploid) be?

Answer 22

~1km (~1000 yards)

Question 23

How big is a human egg cell?

Answer 23

about the size of a grain of salt (e.g. Norton table salt).

Question 24

How does all the DNA fit into the nucleus of a cell?
What is the study of chromosomes called?
cytogenetics

Answer 24

Answer: It is tightly packaged around proteins.

Question 25

At what stage in a cell’s life can one se chromosomes (under a microscope).

Answer 25

During cell division.

Question 26

Explain the difference between divergence and homology with regard to two DNA sequences.

Answer 26

Divergence is the fraction of differences observed, and homology is the fraction of identical sequence

Question 27

What is phylogeny?

Answer 27

The graphical representation of evolutionary history of multiple lineages.

Question 28

What do the nodes of a phylogeny represent?

Answer 28

Hypothetical ancestors.

Question 29

Why is the genetic difference between humans and chimpanzees larger than 2%?

Answer 29

Each species has stretches of DNA that are missing in the other species.

Question 30

Why do human genes not have more than two alleles for each locus in each individual?

Answer 30

Humans are diploid.

Question 31

What is the problem with the classic definition of a gene as “a stretch of DNA that codes for a protein”?

Answer 31

Much of the non-protein coding genome also has functions: RNA genes and enhancers regulate gene expression

Question 32

What is transcription factor (TF)?

Answer 32

A protein that influences the expression of one or more genes

Question 33

Why is East Africa so rich in ancient human fossils?

Answer 33

the continental rift provides ideal conditions for fossilization.

Question 34

Which continent exclusively contains hominid fossils older than 2 million years?

Answer 34

Africa

Question 35

Which were the last two continents settled by ancient humans?

Answer 35

The Americas

Question 36

Mention three extinct mammal species that had their ancient genomes
characterized ?

Answer 36

Neanderthal, Denisovan, Cave Bear.

Question 37

How many different human-like species existed 50,000 years ago?

Answer 37

At least four.

Question 38

What is the study of chromosomes called?

Answer 38

cytogenetics