bio test 4

Question 1

definition of heterochromatin

Answer 1

densely staining chromatin that appears as nodules in or along chromosomes and contains relatively few genes.

Question 2

euchromatin definition

Answer 2

It represents the major genes and is involved in transcription. chromosome material that does not stain strongly except during cell division.

Question 3

difference between euchromatin and heterochromatin

Answer 3

Heterochromatin is highly condensed, gene-poor, and transcriptionally silent, whereas euchromatin is less condensed, gene-rich, and more easily transcribed

Question 4

Gurdon’s nuclear transplant experiment

Answer 4

transplanted nuclei from tadpole cells of Xenopus, and other frog species, into unfertilized Xenopus eggs and observed how the modified eggs proceeded to develop. Gurdon stopped the development of some of the modified eggs, or fixated them, and allowed others to build as far as possible.

Question 5

General CpG

Answer 5

useful markers for genes in organisms containing 5-methylcytosine in their genomes. In addition, CpG islands located in the promoter regions of genes can play important roles in gene silencing during processes such as X-chromosome inactivation, imprinting, and silencing of intragenomic parasites.

Question 6

Positive regulation

Answer 6

increased rate of gene expression

Question 7

negative regulation

Answer 7

inhibits or lowers odds of that specific gene

Question 8

what conditions must be met for the lac operon to be fully functional

Answer 8

Low glucose
High cAMP

lactose

Question 9

what CRP-cAMP does

Answer 9

cAMP readily binds with CAP, and the CAP-cAMP complex binds DNA at a position upstream of the lac operon. The association between RNA polymerase and DNA is enhanced when the CAP-cAMP complex is present.
high glucose low cAMP
low glucose high cAMP

Question 10

totipotent

Answer 10

isolated cell that is able to produce a fertile adult individual

Question 11

where are totipotent stem cells found

Answer 11

only in early embyotic tissues

Question 12

pluripotent

Answer 12

A cell that is able to develop into many different types of cells or tissues in the body.

Question 13

where are pluripotent found

Answer 13

Found in bone marrow, blood and adipose tissue.

Question 14

multipotent stem cells

Answer 14

have the ability to differentiate into all cell types within one particular lineage. There are plentiful advantages and usages for multipotent stem cells. Multipotent Stem cells act as a significant key in procedure of development, tissue repair, and protection.

Question 15

where are multipotent stem cells found

Answer 15

Found in bone marrow, fat tissue, dental pulp, heart tissue, and many other places.

Question 16

pax6 gene

Answer 16

play a critical role in the formation of tissues and organs during embryonic development. The members of the PAX gene family are also important for maintaining the normal function of certain cells after birth

Question 17

enhancers in transcription regulation

Answer 17

help establish the transcriptional program of cells by increasing transcription of target genes.

Question 18

activators in transcription regulation

Answer 18

turn on the expression of genes in a eukaryotic cell.

Question 19

mediators in transcription regulation

Answer 19

relaying signals from TFs directly to the pol II enzyme, thereby facilitating TF-dependent regulation of gene expression.

Question 20

evolution definition

Answer 20

a change in allele or genotype frequency in a population over time

Question 21

difference between natural selection and genetic drift

Answer 21

Genetic drift causes evolution by random chance due to sampling error, whereas natural selection causes evolution on the basis of fitness.

Question 22

three types of selection

Answer 22

Stabilizing selection
Disruptive selection
Directional selection.

Question 23

reproductive isolation

Answer 23

the inability of a species to breed successfully with related species due to geographical, behavioral, physiological, or genetic barriers or differences.

Question 24

adaptation for apes

Answer 24

Having long arms and short legs gives the species a natural quadrupedal posture, which helps reduce stress on their bones and joints due to their great mass. They normally “knuckle walk” on the knuckles of their hands and the palms of their feet, but are also capable of walking bipedally for limited periods.

Question 25

adaptation for amphibians

Answer 25

Skin that prevents loss of water.
Eyelids that allow them to adapt to vision outside of the water.
An eardrum developed to separate the external ear from the middle ear.
A tail that disappears in adulthood (in frogs and toads).

Question 26

adaptation for mammals

Answer 26

Water-repelling fur, tough hides, camouflage, as well as the size and shape of various body parts

Question 27

nodes in phylogenic trees

Answer 27

Nodes are the points at the ends of branches that represent sequences or hypothetical sequences at various points in evolutionary history.

Question 28

how do mass extinctions affect species

Answer 28

it reduces diversity and kills off whole lineages, they can prune entire branches of phylogenetic trees

Question 29

Sahelanthropus tchadensis found in

Answer 29

northern Chad 2001

Question 30

radimus found in

Answer 30

middle of ethiopia

Question 31

ergaster found in

Answer 31

kenya

Question 32

heidelbergensis found in

Answer 32

germany

Question 33

sapiens were found in

Answer 33

ethiopia

Question 34

where were neanderthals found

Answer 34

italian cave

Question 35

the relationship between Mitochondrial DNA, Neanderthals, and Sapiens

Answer 35

The mitochondrial DNA study indicated that there was no genetic input from Neanderthals in modern humans, but the whole-genome study suggests that in fact there was. One suggestion to explain this discrepancy is that the Neanderthal input into modern human populations was from males only.

Question 36

where did neanderthals develop

Answer 36

Africa but migrated to Eurasia

Question 37

when did neanderthals disappear

Answer 37

40,000 years ago

Question 38

where did sapiens develop

Answer 38

africa

Question 39

what form of selection does sympatric speciation relate to

Answer 39

distributive selection, polyploidy

Question 40

definition of sympatric speciation

Answer 40

speciation occurs when two groups of the same species live in the same geographic location, but they evolve differently until they can no longer interbreed and are considered different species.

Question 41

two types of allopatric speciation

Answer 41

vicariance and peripatric

Question 42

Understand the differences and forms of Pre and Post zygotic isolation

Answer 42

the prezygotic prevents the fertilization of the egg while the postzygotic prevents the formation of viable or fertile offspring.

Question 43

prezygotic form

Answer 43

spatial, behavioral, mechanical and temporal isolation.

Question 44

postzygotic form

Answer 44

occurs after members of two different species have mated and produced a zygote. The offspring of such a mating is called a hybrid.

Question 45

biological species concept

Answer 45

organisms that appear to look alike but are different species. a species as members of populations that actually or potentially interbreed in nature, not according to similarity of appearance

Question 46

hybrid means what for the normal distribution curve

Answer 46

mean or middle

Question 47

morphological species concept (house cat and bobcat)

Answer 47

defines species as groups of individuals that are morphologically similar to one another and are morphologically distinct from other such groups.

Question 48

ecological species concept

Answer 48

a set of organisms adapted to a particular set of resources, called a niche, in the environment. bears mate according to their environment. grizzlys on land and polar bears in water