Biology exam

DNA structure

DNA structure

double helix

Codes:
Adenine
Thymine
Guanine
Cytosine

Nucleo Tides

ATAAGC
Complementary = opposite or other/half
TATTCG

Number of chromosomes in a human/potential other animals (take the final number of individual chromosomes and divide it by 2 to get the number of pairs)

46 total chromosomes, 23 pairs of chromosomes per person.

Somatic

46 total chrom

Gamete (sex cells)

23 total chrom (half)

Determination of child's sex

It is determined by the father because of X Y chromosomes

Genotype vs. phenotype

genotype is the collection of alleles

phenotype is the physical expression of the alleles

Heterozygous vs. homozygous

Homozygous dominant - RR

Homozygous recessive - rr

Heterozygous mix of dom/rec - Rr

Sex-linked characteristics (X-linked)

The majority of infected are men (x-linked traits). On the x chromosomes, the X chromosome is affected by illness or disease.

X^B X^b = Female (carrier) X^B y = Male (not affected)

Women are typically carriers

Punnett squares

A chart that shows all the possible combinations of alleles that can result from a genetic cross

3 different types:

Complete: 1 dom, 1 recessive
Incomplete: 1 dom that is not so dominant, 3rd phenotype Ex: (white + Red = Pink)
Codominant: 2 dominant traits, 3rd phenotype

Blood types are determined byGene expression: complete, incomplete, or codominance

4 different types, genotypes of the blood

A: I^A I^A or I^A i
B: I^B I^B or I^B i
AB: I^A I^B
o: i i
On the final it will look like AO or AA for punnet squares!

Use a pedigree to determine genotype and phenotype of offspring

x -- linked chromosomes and autosomal

Organization from individual to biosphere

Species
Population
Community
Ecosystem
Biosphere

Movement of energy food chains and food webs

Sun - producer- primary - secondary - tertiary

Trophic levels

Trophic levels:

Primary producers (plants)(autotroph) -- Primary consumers (herbivores)(heterotroph) --Secondary consumers -- tertiary consumers -- detritivores (decomposers)

Ecological Pyramids

models that show how energy flows through ecosystems

Ex: Top Carnivores, Carnivores, Herbivores,
Producers

Biogeochemical cycles H20, C, N, P

Water cycle (need to know) Nitrogen cycle (need to know)

Population Growth

the increase in the number of individuals in a population

Logistics growth

Growth pattern in which a population's growth rate slows or stops following a period of exponential growth

Exponential growth

Growth pattern in which the individuals in a population reproduce at a constant rate

Carrying capacity and limiting factors

Carrying capacity : average population in a particular area

Limiting factors: Anything that stops population growth or slows it down

What is necessary for Evolution to occur

genetic variation

Natural Selection

A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.

Process that creates variation

Mutations, the changes in the sequences of genes in DNA, are one source of genetic variation.

Different types of isolation

Geographical, temporal, behavioral

Evidence for evolution

fossils

Phylogenetic trees

Branching diagrams that depict hypotheses about evolutionary relationships.

Analogous vs Homologous structures

Homologous structures share a common ancestry, but not necessarily a common function.

Analogous structures share a common function, but do not share a common ancestry.

Embryology

similarities in embryos explained by all descending from common ancestor

Mutualism

symbiotic relationship in which both species benefit from the relationship

Commensalism

one organism benefits and the other is unaffected

Parasitism Competition

occurs when an organism lives in of its host for an extended period of time or for its entire life cycle

Predator/prey relationships

mechanism of population control in which a population is regulated by predation