Bio 100 Unit #2

Question 1

This is the function of tRNA.

Answer 1

tRNA transports amino acids to the ribosome during protein synthesis.

Question 2

What is a codon and what molecule has them?

Answer 2

A codon is a sequence of 3 nucleotides on mRNA that codes for an amino acid.

Question 3

What 2 pyrimidines are found in RNA?

Answer 3

cytosine and uracil

Question 4

What can be found in an RNA nucleotide?

Answer 4

1 phosphate
1 Ribose sugar
1 nitrogen base: either A, U, G or C

Question 5

When during the cell cycle is DNA copied?

Answer 5

S phase of interphase

Question 6

What happens during ANAPHASE of mitosis?

Answer 6

Sister chromatids are pulled apart.

Question 7

What is chromatin?

Answer 7

Loosely coiled DNA found in the nucleus of a cell in interphase, thus NOT dividing.

Question 8

What are ribosomes made of?

Answer 8

RNA - specifically rRNA

Question 9

How many chromosomes are found in a body cell? Gamete?

Answer 9

46 in body cells

23 in gametes such as sperm or egg cells

Question 10

What kind of cells undergo mitosis?

Answer 10

Body cells, like muscle or skin cells, undergo mitosis.

Question 11

How are DNA & RNA polymerase the same and different?

Answer 11

Both are enzymes used to unzip DNA. DNA polymerase also adds DNA nucleotides during replication. RNA polymerase adds nucleotides for transcription.

Question 12

How many chromosomes are found in a normal karyotype?

Answer 12

46 total: 44 autosomes and 2 sex chromosomes

Question 13

What is the longest phase of the cell cycle?

Answer 13

Interphase

Question 14

What phase of mitosis overlaps with cytokinesis?

Answer 14

Telophase

Question 15

What are sister chromatids?

Answer 15

Identical copies of DNA that are held together by a centromere. They can be seen during cell division.

Question 16

What DNA bases are complimentary to:

AGCT?

Answer 16

TCGA

Question 17

What RNA bases are complimentary to DNA bases: AGCT

Answer 17

UCGA

Question 18

What does the codon AUG code for?

Answer 18

2 things: “Start” and the amino acid, Methionine

Question 19

How is a phenotype different than a genotype?

Answer 19

Phenotypes describe the physical expression of the genotype, which is the gene pair for a trait.

Question 20

Describe meiosis.

Answer 20

Produces haploid gametes
Goes through 2 divisions
Halves the # of chromosomes in cells

Question 21

When are replicated chromosomes visible?

Answer 21

Prophase and metaphase

Question 22

What’s the difference between Homozygous and Heterozygous?

Answer 22

Homozygous: BB or bb
Heterozygous: Bb

Question 23

What is a sex linked gene?

Answer 23

A gene found on a sex chromosome, usually the X.

Question 24

What are homologous chromosomes?

Answer 24

Matching chromosomes in that they are the same size/shape but also carry genes for the same traits. You would inherit 1 from each parent.

Question 25

How is cytokinesis in animal cells different than in plant cells?

Answer 25

Animal cells form an invagination called a cleavage furrow while plants form a cell plate.

Question 26

Which bases are purines?

Answer 26

Adenine and Guanine

Question 27

Which bases are pyrimidines?

Answer 27

Cytosine, Thymine, and Uracil

Question 28

How do DNA and RNA differ?

Answer 28

DNA: double helix, 2 sided, Thymine, Deoxyribose. RNA: single sided, Uracil, Ribose

Question 29

What are somatic cells?

Answer 29

Diploid body cells

Question 30

What are gametes?

Answer 30

Haploid sex cells like sperm cells

Question 31

Contrast co-dominance with incomplete dominance.

Answer 31

Co-dominance: Both alleles are expressed | Incomplete Dom: There is a blending effect with an intermediate form of each phenotype

Question 32

Who discovered the shape of DNA?

Answer 32

James Watson and Frances Crick, with the help of Rosalind Franklin and Maurice Wilkins

Question 33

What is a kinetochore?

Answer 33

Protein found near the centromere where spindle fibers attach.

Question 34

What kind of sex chromosomes are found in male & female gametes?

Answer 34

Females: 1 X only Males: 1 X or 1 Y

Question 35

Where do transcription and translation occur?

Answer 35

Transcription: nucleus Translation: cytoplasm

Question 36

What are the 4 phase of mitosis in order?

Answer 36

P, M, A, T

Question 37

How does cell division occur?

Answer 37

First the nucleus is divided (mitosis) then the rest of the cell splits (cytokinesis).

Question 38

What kind of bonds are found in DNA?

Answer 38

Strong covalent bonds down each side and weak hydrogen bonds across the molecule.

Question 39

What are carcinogens?

Answer 39

Agents such as U.V. that can mutate DNA.

Question 40

What is meant by a polygenic trait?

Answer 40

The trait is controlled my multiple genes, not just alleles.

Question 41

T or F: asexual reproduction produces a lot of diversity.

Answer 41

False: offspring would be clones of the parent organism

Question 42

What are the 3 parts of a nucleotide?

Answer 42

phosphate, sugar, nitrogen base

Question 43

What is a mutation?

Answer 43

Any change to the sequence of DNA

Question 44

What is a gene?

Answer 44

A section of DNA that codes for a protein.

Question 45

What is the ultimate source of variation?

Answer 45

Mutations

Question 46

How many genes are involved in epistasis?

Answer 46

More than 1, because one will have the capacity to allow or deny the expression of another gene. Ex: fur color in labs

Question 47

What is pleiotropy?

Answer 47

One gene causes a phenotype that has a cascade effect on other phenotypes. Ex: sickle cell gene

Question 48

What is a centriole?

Answer 48

An organelle involved in dividing chromosomes.

Question 49

What is a centromere?

Answer 49

The spot where sister chromatids attach.

Question 50

What is an anticodon?

Answer 50

3 nucleotides of tRNA that is complimentary to the codon in mRNA

Question 51

What is a tetrad?

Answer 51

A tetrad forms when homologous chromosomes attach together during prophase of meiosis.

Question 52

What happens during cross-over?

Answer 52

Tetrads swap genes to create diversity.

Question 53

Does dominant mean most common?

Answer 53

No - it means that the dominant gene can mask the presence of the recessive gene. It may or may not be the most common in a gene pool.

Question 54

Be able to interpret genetic crosses using Punnett Squares.

Answer 54

OK!

Question 55

Be able to identify various stages of the cell cycle from a diagram.

Answer 55

OK!