Chpter 46 Reproduction Flashcards
What is sexual reproduction?
Sexual reproduction is the creation of offspring by the fusion of a male gamete (sperm) and a female gamete (egg) to form a zygote.
What is asexual production?
The creation of offspring without the fusion of egg and sperm.
How do invertebrates reproduce?
They reproduce asexually by fission (separation of a parent into two or more individuals of about the same size.)
What is budding?
In budding, new little ones grow from parts of bigger ones.
- Budding is not considered diverse.
What is fragmentation, and what happens?
Fragmentation means breaking the body into pieces, and some or all of those pieces grow into adults. To happen, fragmentation needs regeneration, which is the regrowth of lost body parts.
What is Parthenogenesis?
Parthenogenesis is when a new individual grows from an egg without needing a father to fertilize it.
sexual reproduction
Sexual females have half as many daughters as asexual females. This is called the “twofold cost” of sexual reproduction because sexual females invest more resources in making offspring. Even though sexual reproduction is more costly, almost all types of living things with cells that have a nucleus (eukaryotic species) still reproduce this way.
What advantages does sexual reproduction have?
- genes mix up which causes many benefits.
- When offspring have more variety, it helps parents because they are more likely to have some babies that can survive in different environments that keep changing.
- An increase in the rate of adaptation
- Mixing up genes and getting rid of bad ones from a group of creatures.
Reproductive cycles are controlled by?
- Reproductive cycles are controlled by hormones and environmental cues
- Most animals exhibit reproductive cycles related to changing seasons
- Because seasonal temperature is often an important cue in reproduction, climate change can decrease reproductive success
ovulation
This is when a female’s body releases an egg that’s ready to be fertilized.
reproductive cycles
- Ovulation: This is when a female’s body releases an egg that’s ready to be fertilized.
- Midpoint of a female cycle: A female’s body goes through a monthly cycle, and ovulation usually happens in the middle of this cycle.
- Reproductive cycles related to changing seasons: Many animals have times of the year when they’re more likely to have babies. They might do this when the weather is good and food is plentiful, like in spring or summer. So, their baby-making schedule is linked to the seasons.
parthenogenesis that involves the doubling of chromosomes after meiosis
means a female can make babies on her own by making special eggs with extra genetic material.
what is hermaphrodites ?
Hermaphroditism is when one living thing has both male and female reproductive parts. This means they can make both eggs and sperm. So, when two hermaphrodites meet, they can mate and exchange both eggs and sperm to make babies. Some hermaphrodites can even fertilize their own eggs without needing another partner.
sex reversals
Sometimes, in certain species, individuals can change from being one sex to another.
external fertilization
extranal fertilization happens when a female releases eggs outside of her body, and then those eggs get fertilized by sperm from a male in the outside environment, like in water.
internal fertilization
- Internal Fertilization: Sperm from a male goes into the female’s reproductive system, where fertilization happens.
2.Requirements: To do this, animals need behaviors and body parts that fit together for mating.
3.Timing and Signals: Successful fertilization depends on mating at the right time, signaled by environmental cues, chemicals, and courtship behavior.
Gamete Production & Delivery
- Sexual Reproduction: Animals need to make sex cells called gametes to reproduce sexually.
- Gonads: Most animals have organs called gonads that make gametes.
- Gamete Production: Some animals have simple systems where gametes form from basic tissue.
- Elaborate Systems: Other animals have complex systems with tubes and glands that carry, feed, and protect gametes and babies.
- Insects: Many insects have separate sexes with complicated reproductive parts.
- Spermatheca: Female insects often have a special place called a spermatheca to store sperm from mating.
what’s a Cloaca?
- Cloaca: It’s like a shared door in animals where poop, pee, and reproductive stuff come out from. It’s common in animals like birds and reptiles.
- Mammals: Most mammals have separate doors for poop and pee, unlike other animals. So, they don’t have a cloaca.
human reproduction
- Ovaries: They’re like special factories in the female body where eggs are made.
- Follicles: Inside the ovaries, there are small pockets called follicles. Each follicle has a baby egg inside, called an oocyte, and some helper cells around it.
- Ovum Development: Every month, one of these baby eggs grows up and becomes a mature egg, which we call an ovum. This process is called oogenesis.
ouvulation:
It’s when a mature egg is released from a little pocket called a follicle. Before the egg comes out, the follicle cells make a hormone called estradiol.
corpus luteum:
After the egg leaves, the empty pocket turns into a new structure called the corpus luteum. This mass makes hormones like estradiol and progesterone.
Hormones and Pregnancy:
These hormones help if a woman gets pregnant by keeping the womb ready. If there’s no pregnancy, the corpus luteum breaks down.
Oviduct or Fallopian Tube:
It’s like a tube that connects the ovary to the uterus, which is where a baby grows.
Cilia:
These are tiny hair-like structures in the tube that help move the egg from the ovary to the uterus.
Uterus or Womb:
It’s a special place where a baby can grow inside the body. The lining of the uterus, called the endometrium, has lots of blood vessels.
Cervix:
This is the lower part of the uterus that’s narrow and connects to the vagina, which is the opening outside the body.
vagina
is a thin-walled chamber that is the repository for sperm during copulation and serves as the birth canal
parts of the Vagina?
The vagina opens to the outside at the vulva, which consists of the labia majora, labia minora, hymen, and clitoris=(The clitoris has a head called a glans covered by the prepuce)
Blood Vessels and Nerve Endings of the vagina:
The vagina, labia minora, and clitoris have lots of tiny blood vessels, and the clitoris has many nerves, which make it sensitive to touch.
Mammary Glands
They’re not part of the reproductive system but are vital for mammal moms.
Milk Production: Inside these glands, small sacs make and release milk.
Male Anatomy
-
External Organs: These are the parts you can see outside the body, like:
the scrotum (where the testicles are) and the penis. -
Internal Organs: Inside, there are :
the gonads (testicles), which make sperm and hormones, and accessory glands that help with sperm and semen production.
Testes
These are the male gonads. They have coiled tubes where sperm form.
Sperm Formation:
Sperm are made in these tubes called seminiferous tubules.
Temperature and Sperm:
Sperm need lower temperatures to form properly.
Scrotum:
In many mammals, the testes are outside the body in a sack called the scrotum, where it’s cooler.
Sperm Movement:
Sperm develop in the seminiferous tubules within the testis and mature as they pass through the coiled tubes of the epididymis.
Ejaculation Process:
When a man ejaculates, sperm travel through two muscular tubes: the vas deferens and the ejaculatory duct. Finally, they exit the body through the penis via the urethra.
