Sex and Behaviour Flashcards Preview

Advanced Higher Biology: Unit 2- Organisms and Evolution > Sex and Behaviour > Flashcards

Flashcards in Sex and Behaviour Deck (26)
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1
Q

Why are eggs are much larger and fewer in number?

A

Due to the presence of an energy store

2
Q

Why do females make a greater sexual investment?

A

due to the production of a lower number of larger gametes.

3
Q

A far greater investment is made by females due to the production of a lower number of larger gametes. What effect does this have on their chance of reproductive success and the chance of passing on genes?

A

their chance of reproductive success is lower and the chance of passing on genes is reduced.

4
Q

In mammals, it is typically the female who have a relatively larger parental investment in producing each offspring. Why is this the case?

A

 Placental Nourishment
 Lactation – feeding the young
 Post-natal care and protection

5
Q

What are sessile organisms?

A

Sessile organisms are those that are fixed to a surface and therefore cannot move.

6
Q

How do slow moving and sessile organisms reproduce?

A

Slow moving and sessile organisms are often hermaphroditic or employ parasitism as a reproductive strategy. Barnacles, for example, are hermaphroditic. They use extremely long sex organs to reach another for the transfer of sperm.

7
Q

What can parental investment be? What benefit can it bring?

A

Parental investment is costly but increases the chance that young will survive.

8
Q

Give the characteristics of a r-selected species. (9)

A
Unstable environment 
Short maturation time
Short life span
Usually high death rate 
Many offspring produced per reproductive episode
Usually one reproduction in lifetime
Early in life - Timing of first reproduction
Small size of offspring or eggs
No parental care
9
Q

Give the characteristics of a k-selected species. (9)

A
Stable environment 
Long maturation time
Long life span
Usually low death rate
Few offspring produced per reproductive episode
Often several reproductions in lifetime
Later in life - Timing of first reproduction
Large size of offspring or eggs
Often extensive parental care
10
Q

What is a survivorship curve?

A

A survivorship curve is a graphic representation of the number of individuals in a population that can be expected to survive to any specific age.

11
Q

What is monogamy?

A

one male mating with one female

12
Q

What are the two types of polygamy? What do they mean?

A

Polygamy:

  • Polyandry - One female and multiple males
  • Polygyny – One male and multiple females
13
Q

What is courtship?

A

Courtship is a specialised behaviour in animals that attracts a member of the opposite sex and leads to mating.

14
Q

What is sexual dimorphism?

A

Sexual Dimorphism is defined as any physical differences between males and females.

15
Q

What are the three main physical differences between males and females?

A

Size – Males are often larger than females.
Colouration – Females are inconspicuous, and males are very conspicuous using colour to display during courtship and territorial behaviour.
Secondary Structures – Males tend to have adornments such as antlers, ornate plumage or a mane.

16
Q

What is reverse sexual dimorphism?

A

Reverse sexual dimorphism is when the normally inconspicuous female is larger or more ornate than the male.

17
Q

Describe male-male rivalry.

A

Males demonstrate different strategies to gain access to females to ensure successful mating:
 Acquiring and defending territories and harems – engaging in direct conflict with other males – superior size and weaponry ensuring success – the alpha male approach.
 Adopting the role of a ‘sneaker’ or a ‘satellite’ male – not engaged in direct conflict – seeking alternative opportunities to mate.

18
Q

What does sneaking behaviour refer to?

A

Sneaking behaviour refers to a strategy that allows smaller, less threatening males to more stealthily access to a female partner, often avoiding alterations with dominant males.

19
Q

Who retains primary control over reproduction?

A

females

20
Q

What does male courtship and appearance provide females with?

A

Male courtship and appearance provides, females with honest signals of male fitness.

21
Q

What does an impressive courtship display or good appearance indicate?

A

An impressive courtship display or good appearance indicates a healthy male with a low parasite burden and the presence of advantageous genes – both indicators of ‘fitness’.

22
Q

What do females use honesty signals for?

A

Females use honesty signals to choose healthier males in order to increase their own fitness and reproductive success.

23
Q

What is lekking?

A

During the breeding season males cluster at a communal display area or lek – displaying and possibly fighting to attract females.

24
Q

What does lekking allow?

A

This allows female choice. Females observe the display enabling them to select the fittest male who they will then mate with.

25
Q

What can successful courtship in birds and fish can be a result of?

A

species- specific sign stimuli and fixed action pattern responses.

26
Q

What is imprinting?

A

Imprinting is an irreversible, developmental process that occurs during a critical time period in young birds.