Genes

Question 1

Gene

Answer 1

Unit of heredity, regions of chromosomal DNA encoding polypeptides and RNAs

Question 2

Intron length

Answer 2

Short in unicellular/oligocellular euk, many kb in multicellular euk

Question 3

Exon length

Answer 3

Usually short, encoding for fewer than 100 amino acids

Question 4

Intron-early hypothesis

Answer 4

Interrupted genes that correspond to proteins or independently functioning noncoding RNA probably originated in interrupted form

Question 5

Intron-late hypothesis

Answer 5

Earliest genes did not contain introns

Question 6

Two parity rules

Answer 6

1) A=T, G=C 2) Equal amounts of A and T, and G and C, found on stretch of single-stranded RNA

Question 7

Homologous genes

Answer 7

Share common features and common ancestor

Question 8

Paralogous genes

Answer 8

Homologs within same species

Question 9

Orthologous genes

Answer 9

Homologs that diverged after a speciation event but have a conserved function

Question 10

Housekeeping gene

Answer 10

A gene that is (theoretically) expressed in all cells because it provides basic functions

Question 11

Some ____ correspond to protein functional domains

Answer 11

Exons

Question 12

What suggests that introns do not separate functional domains?

Answer 12

Varying intron positions in actin gene family

Question 13

The use of _______ allows multiple variants of a polypeptide chain (3)

Answer 13

Alternative initiation or termination codons, alternative splicing, mRNA read in different reading frames

Question 14

The number of genes in eukaryote genomes is ______ to genome size

Answer 14

Not proportional

Question 15

Total amount of DNA in the genome

Answer 15

C-value

Question 16

Lack of relationship between the DNA-content of organism and it’s coding potential

Answer 16

C-value paradox

Question 17

Majority of repetitive DNA content

Answer 17

Transposons

Question 18

Polypeptides are generally encoded by sequences in _____

Answer 18

Nonrepetitive DNA

Question 19

Luxury genes

Answer 19

Gene encoding a specialized function (usually) in large amounts in certain cell types

Question 20

In any particular cell, most genes are expressed at a ______

Answer 20

Low level

Question 21

Not all genes are essential. In yeast and flies deletions of less than ___% have detectable effects

Answer 21

50

Question 22

Repeated sequences account for more than ___% of the human genome

Answer 22

50

Question 23

__% of human genome consists of exons

Answer 23

1

Question 24

Human genome has about _____ genes

Answer 24

20,000

Question 25

Mitochondria (mtDNA) and chloroplasts (cpDNA or ctDNA) have genomes that show ________

Answer 25

Non-Mendelian inheritance (typically maternal)

Question 26

_____ between multiple copies allows the active genes to be maintained during evolution in Y chromosome

Answer 26

Gene conversion

Question 27

Region of the animal mitochondrial DNA molecule that is variable in size and sequence and contains the origin of replication

Answer 27

D loop

Question 28

Animal cell mtDNA encodes for?

Answer 28

13 proteins, 2 rRNAs, 22 tRNAs

Question 29

Animal cell mtDNA encodes for?

Answer 29

Very compact: 13 proteins, 2 rRNAs, 22 tRNAs