ch 5 test

Question 1

who was Gregor Mendel?

Answer 1

an Austrian monk from the 1500 who became famous for his studies in genetics. studied traits in pea plants

Question 2

why were pea plants such a good choice for his study of genetics?

Answer 2

reproduce quickly, easily observable traits, experimenter can control which pairs of plants reproduce

Question 3

how can you tell if an organism is true breeding?

Answer 3

plants that produce offspring with the same traits

Question 4

what is hybrid?

Answer 4

plants produced by a cross between parents with different traits

Question 5

when Mendel crossed a true-breeding purple plant with a true-breeding white flowered plant, what color were the offspring?

Answer 5

only purple

Question 6

when he crossed two of the offspring, what color were the flowers in the plants that were produced?

Answer 6

the white flowers reappeared- 75% purple 25% white

Question 7

what does the x shaped object represent?

Answer 7

a chromosome

Question 8

in a eukaryotic cell, where would you find these x’s?

Answer 8

in the nucleus

Question 9

what 2 things make up the x’s

Answer 9

DNA and protein histones

Question 10

in genetics, what does an uppercase letter represent?

Answer 10

dominant alleles

Question 11

what does the lowercase letter represent?

Answer 11

recessive alleles

Question 12

which type of trait can be hidden?

Answer 12

recessive

Question 13

what is YY?

Answer 13

homozygous

Question 14

what is Yy

Answer 14

heterozygous

Question 15

what is incomplete dominance?
(ex.)

Answer 15

neither of the parent’s traits are fully dominant (cow’s hair color)

Question 16

what is polygenic inheritance?

Answer 16

when multiple genes determine the phenotype

Question 17

something that might affect the phenotype of an organism

Answer 17

chemicals in the soil

Question 18

what does DNA stand for

Answer 18

deoxyribonucleic acid

Question 19

what is the shape of DNA

Answer 19

shaped like a twisted ladder (double helix)

Question 20

which 2 molecules form the DNA “backbone”

Answer 20

suger and phosphate

Question 21

what are the bases?

Answer 21

adenine, cytosine, guanine, and thymine

Question 22

what is replication

Answer 22

when a cell makes a copy of its DNA

Question 23

describe the steps of a DNA molecule as it replicates itself

Answer 23

it unzips down the middle
new nucleotides are added to build the missing half

Question 24

the job of DNA is to carry the instructions needed to make

Answer 24

proteins

Question 25

what happens inside a cell in transcription?

Answer 25

an mRNA strand is made using the instructions in DNA

Question 26

what happens in translation?

Answer 26

ribosomes use the instructions in mRNA to make a chain of amino acids that form a protein

Question 27

which organelle reads the instructions in mRNA to make a chain of amino acids that form a protein?

Answer 27

ribosomes

Question 28

how many bases make a codon

Answer 28

3

Question 29

give 2 examples of proteins that are made using the instructions in DNA

Answer 29

antibodies
melanin

Question 30

what is mutation?

Answer 30

a mistake in DNA

Question 31

3 examples of things that might cause a mutation in DNA

Answer 31

1 chemicals in environment 2 some viruses 3 UV radiation

Question 32

example of a mutation that would be good for an organism

Answer 32

a change in color that helps an animal camouflage itself

Question 33

example of a mutation that would be bad for an organism

Answer 33

change in body shape that makes it harder to move