Animal Reproduction

1
Animal Reproduction
2
Memory Check Answers

• 1. Explain how certain animals can reproduce
  asexually. Give one example
• A mature individual will produce a bud that
  develops directly on the parent. When the bud is
  mature, it breaks off and becomes independent.
  Example Sponges and Hydras

3

• 2. Why must the spermatozoa and ova combine in a
  moist environment?
• Both the male and female gametes are very fragile
  cells that will die if they dry out. Moisture
  also keeps the egg membrane more supple, which
  allows the spermatozoa to penetrate more easily.
  Lastly the spermatozoa can only move in a moist
  environment

4

• 3. What is the difference between
• A) Mating and Fertilization
• Mating when two individuals of an animal species
  unite to combine gametes
• Fertilization When the male and female gametes
  combine
• B) Internal and External Fertilization
• External Gametes combine outside the bodies of
  both parents
• Internal Spermatozoa enter the female and
  migrate to the ovum or ova
• C) A Cloaca and a Penis
• Cloaca Where sperm, urine and feces are released
• Penis Where sperm and urine are released

5

• 4. During a full moon, the entire population of a
  colony of sea anemones release their spermatozoa
  and eggs at the same time. Why?
• This helps increase the probability that the eggs
  will be fertilized since there will be more
  spermatozoa present

6

• 5. Turtles lay hundreds of eggs at a time. Birds
  usually lay fewer than 10. How can you explain
  the difference.
• When turtles hatch, they are able to find their
  own food and defend themselves they do not
  require further parental care. When birds hatch
  they must be fed, protected and taught how to fly
  so mothers could not handle too many at one time

7

• 6. Describe the fertilization process of
  hermaphrodites.
• Both members of the species produce both an egg
  and sperm. When they mate each injects semen
  into the genital opening of the other to
  fertilize the others egg. They cannot
  self-fertilize

8
Reproduction in Animals

• Asexual Reproduction
• A single living organism that can produce one or
  more identical individuals
• Sexual Reproduction
• The combination of male and female gametes, each
  of which contain half of the genetic material
  necessary to the future offspring.

9

• Gamete The male or female reproductive cell that
  can unite with another, similar cell from the
  opposite sex, through a process called
  fertilization
• Sperm The male reproductive cell, which includes
  a tail for movement (the whole structure is
  called a spermatozoa)
• http//www.youtube.com/watch?v6rauO_M9tb4

10

• Ovum The female reproductive cell, the plural is
  ova. Commonly called an egg.
• http//www.youtube.com/watch?v2-VKgdhfNpYfeature
  related

11
Steps of Vertebrate Reproduction

• 1. Male gamete fuses with a female gamete
• 2. Fusion produces a cell called a zygote that
  contains complete genetic material
• 3. The zygote divides and transforms into an
  embryo with many cells

12

• 4. The embryo develops into a small animal
• 5. When the animal becomes an adult it will
  produce gametes and reproduce

13
Conditions for Sexual Reproduction

• 1. Male and female gametes must be at the same
  place at the same time
• 2. The zygote must obtain the nutrients and
  protection it needs to survive including warmth
  and moisture

14

• Oviparous Lays eggs- reptiles, birds,
  amphibians, insects and fish
• Viviparous Fertilized ovum develops completly
  inside the mothers body- almost all mammals
• Ovoviparous Produce eggs but do not lay them,
  instead keep them inside their body- snakes