The short answer is no, not all animals are either male or female. There is a long list of asexual animals and also hermaphroditic animals.
No. Tigers can be either male or female.
Tigers, like all mammals, are either male or female.
There were pairs (male and female) of either two or seven of each kind on the ark. The Bible says they entered the ark in twos. Many aquatic animals would not have needed to enter the ark at all.
Just like all mammals, some are males, some are females.Giraffes can be either female or male but not both.
No. However, the male may pressure the female to have sex. Animals have no dignity after all. ^^
Yes, male cheetahs have a penis and female cheetahs give birth.
All female animals get pregnant so that means all animals are sexual because a male animal had to have sex with the female to get her pregnant. ex: a male and female dog have sex the female is pregnant therefore a baby if animals don't have sex then those kind of animals don't be born therefore the population stays the same instead of it rising
Flowers can be either male, female or both. I'm not sure if the periwinkle is any specific 'gender'. I'd say the either or both applies for all flowers.
There are indeed female trees, millions of them. With any separate-sexed (dioecious) species, one tree will be all male, and another will be all female. For example, willow trees will either be males, or females. Aspens or cottonwood trees will each be either a male, or a female tree. Many shrubs, too, will be separate-sexed...for example, a yew or juniper bush will either be a male, or a female. It is important to note, too, that male plants produce allergenic pollen, and female plants do not produce any pollen. For further info on this, see the book, Allergy-Free Gardening, by Thomas Leo Ogren.
Im presuming you mean animals. All animals species and even some plant species need a female and male to reproduce. Similar to humans animals need to exchange male and female juices to reproduce. Suprisingly enough though some male animals actually carry the young.
Same way that all mammals get pregnant. Male animals mates with the female, placing sperm in the female, which fertilizes the eggs of the female.
All bulls are male. Cows are female, mostly.