BIO120H1 Midterm: study guide for term test 2

Which of the following are requirements for evolution by naturalselection?

I Environmental change

II Differential survival and reproduction

III Heritability of phenotypic variation

IV Variation in phenotype

V Sexual reproduction

A) II, III, V
B) II, III, IV
C) I, II, IV
D) III, IV, V
E) II, IV, V

1. (a) Discuss ways in which phenotypic variation occurs withinpopulations. (b) Explain how phenotypic variation aids in thesurvival of the fit.

Write your response below.

a) phenotypes can be caused by

• genetic variation

• environmental factors

• Both.

Genetic variation cause phenotypic change. when two geneticallydifferent parents mate then there are chances to get phenotypicvariations. Like a mule is crossbreed between a horse and a donkey.while environmental factors are things in an organism'ssurroundings that can influence it in various ways. For example,body weight in humans may be influenced by genes but is alsoinfluenced by diet. In this case, diet is an example of anenvironmental factor.

I NEED B ANSWERED!!!

Is A correct? I might be wrong I'm terrible at thisclass please help

1. Late stage succession communities typically: a) contain more equilibrial than opportunistic species b) are more diverse than disturbed communities c) are more diverse than early stage succession commmunities d) contain more opportunistic species than equilibrial species e) suffer higher rates of disturbance

2. Phenotypic plasticity is when: a) Organisms adapt their genotype to the local environment b) Individuals with different phenotypes show plasticity in their size c) Organisms with different genotype express different phenotypes in the same environment d) Plasticity in the environment causes different genotypes to survive leading to different phenotypes e) Organisms express different phenotypes depending on the local environment but have the same genotype

3. Terrestrial areas that are saturated with water, either permanently or seasonally, are typically known as what type of ecosystem. f) Grasslands g) Heathlands h) Litholands i) Wetlands j) Littoral

4. Briefly explain two ways that excess climate gas emissions are changing the world’s physical environment