L.4 Evolution & Genetics

Question 1

hereditary units

Answer 1

genes

Question 2

gametes

Answer 2

reproductive cells

Question 3

locus

Answer 3

gene’s location

Question 4

a single organism passes on genetic information to its offspring in the form of an exact genetic copy of themselves

Answer 4

asexual reproduction

Question 5

the offspring of asexual reproduction, genetically identical individuals

Answer 5

clone

Question 6

two parents have an offspring with genetic variability from unique combos of genes from both parents

Answer 6

sexual reproduction

Question 7

ordered display of chromosomes

Answer 7

karyotype

Question 8

two identical chromosomes (same length, staining pattern, centromere position)

Answer 8

homologs or homologous chromosomes

Question 9

X and Y chromosomes

Answer 9

sex chromosomes

Question 10

all chromosomes except X and Y

Answer 10

autosomes

Question 11

union of gametes, fusing their nuclei (like sperm and egg)

Answer 11

fertilization

Question 12

diploid combo of gametes, the resulting fertilized egg

Answer 12

zygote

Question 13

Explain the following to your friend:
“In a literal sense, children don’t inherit particular physical traits from their parents, it is the genes that are actually inherited

Answer 13

The physical traits derived from our genes are called phenotype. We don’t inherit phenotypes from our parents. We inherit genes and genotypes from our parents. Both of my parents have hazel eyes. I did not inherit my parents hazel eyes. Neither did any of my sisters. The reason we didn’t inherit these physical traits is because our DNA doesn’t code for the phenotype “hazel eyes”. Both my parents have the gene for brown eyes, and because of this my siblings all have brown eyes. We inherit genes that in turn determine our physical traits.

Question 14

Humans have ____ chromosomes that make up ____ pairs of genes

Answer 14

46, 23

Question 15

List the 3 different sexual life cycles and describe each

Answer 15

Sexual life cycles all happen by meiosis and fertilization, the timing of these things vary the life cycles between animals, plants, and fungi.
In animals, the gametes are the only haploid cells. Meiosis occurs during the production of gametes, which don’t divide anymore because they’re haploid. THen they move to fertilization, creating a diploid zygote. The zygote divides by mitosis, creating another animal.

Plants undergo alteration of generations. The original multicellular organism is called the sporophyte, and produces not gametes, but haploid spores, by meiosis. Those spores embed and divide mitoticallly to make a whole new organism, gametophyte. The gametophyte undergoes mitosis, as well, producing gametes, still haploid. These gametes fertilize, creating a diploid zygote that will develop into our sporophyte.

Fungi also produce differently. After forming a diploid zygote, meiosis occurs without producing a multicellular diploid offspring. Meiosis produces haploid cells that divide by mitosis, producing unicellar organisms or haploid multicellular organism. The haploid organism undergoes mitosis, producing gametes. The only diploid stage of fungi’s sexual life cycle is the zygote.

Question 16

What 3 mechanisms of cell division contribute to genetic variability? Explain or describe each mechanism.

Answer 16

Independent assortment of chromosomes- chromosomes align randomly at the metaphase plate which when separated form new daughter cells that offer genetic variability.

Crossing over- two sister chromatids swap genetic information at chiasma.

Random Fertilization- in humans, each member produces about 8.4 million (2^23) different combos of our genes in our gametes, when fertilized that’s 70 trillion different possible combos (2^23x2^23). Fertilization is random. You aren’t just one in a million. You are a 1/70Trillion.

Question 17

alternate versions of a gene

Answer 17

alleles

Question 18

2 of the same alleles, either both dominant or both recessive

Answer 18

homozygote/homozygous

Question 19

2 different alleles, dominant and recessive

Answer 19

heterozygote/heterozygous

Question 20

the way a gene presents physically (ex: brown eyes)

Answer 20

phenotype

Question 21

genetic make-up (ex: Bb)

Answer 21

genotype

Question 22

family tree that describes the interrelationship of parents and children across generations

Answer 22

pedigree

Question 23

heterozygous individuals who carry the recessive gene but are phenotypically normal

Answer 23

carrier

Question 24

probability tool to predict offspring

Answer 24

Punnett squares

Question 25

sum of all alleles in population

Answer 25

gene pool

Question 26

changes in DNA

Answer 26

mutation

Question 27

the process by which different kinds of living organisms are thought to have developed and diversified from earlier forms during the history of the earth

Answer 27

evolution

Question 28

popularized evolution with his book On the Origin of Species

Answer 28

Charles Darwin

Question 29

living things that influence an environment

Answer 29

biotic factors

Question 30

change in an organism’s genetic makeup, DNA, that occurs through natural selection of advantageous traits for survival over an extended period of time.

Answer 30

Biologic Change

Question 31

the organization and identification of an organism from general to specific by identifying the organisms’ Domain, Kingdom, Phylum, Class, Order, Genus, and Species

Answer 31

Biological classification

Question 32

the analysis of body structures (body systems , skeletal systems) between two or more different species that provides insight into the genetic/biologic similarities and differences across species

Answer 32

Comparative anatomy

Question 33

likenesses in the embryonic stage of development between different species; evidence for evolution

Answer 33

Embryological similarities

Question 34

the complete elimination (dying out) of a species due to the species inability to survive and therefore adapt to its environment.

Answer 34

Extinction

Question 35

Similar body structures and systems between different species; evidence for biologic evolution

Answer 35

Homologous Body Structures

Question 36

the theory that organisms/species change over time, caused by the natural selection of advantageous traits for survival in a particular environment. This theory also proposes that all organisms evolved from a common ancestor.

Answer 36

Theory of Evolution

Question 37

a beneficial trait that helps an organism survive in its environment

Answer 37

Adaptation

Question 38

the characteristics that make members of the same species different from one another

Answer 38

Genetic Variation

Question 39

explanation of how organisms in a population develop traits that allow them to survive and reproduce

Answer 39

Natural Selection